Collapsible carton



April 9, 1957 B. D. OSTEEN COLLAPSIBLE CARTON Filed Sept. 30, 1955 lfforbe s COLLAPSIBLE CARTON Belmont D. Osteen, Birmingham, Ala., assignor to Birmingham Paper Company, a corporation of Alabama Application September 30, 1955, Serial No. 537,709

1 Claim. (Cl. 229-34) This invention relates to a collapsible carton formed from an integral blank and has for an object the provision of such a carton which may be folded down fiat for shipping and storage and then erected by the user without weakening the corners or sides adjacent the corners.

Another object of my invention is to provide a collapsible carton of the character designated which shall include improved locking means for holding the carton in erected position.

A still further object of my invention is to provide a collapsible carton which shall be simple of construction, economical of manufacture and which may be collapsed or erected with a minimum of effort.

Heretofore in the art to which my invention relates various forms of collapsible cartons have been proposed. However, with such cartons the corner portions and the walls adjacent the corners are weakened by folding the sides and ends inwardly. Also, the means for holding the carton in erected position has been complicated, thus making it difficult to manufacture and assemble the com pleted carton.

I overcome these difficulties and provide a very sturdy carton, when erected, by constructing the carton whereby the side and end walls are not bent or otherwise weakened when collapsed or erected and by providing simple and effective means for locking the carton in erected position.

A carton embodying features of my invention is illustrated in the accompanying drawings forming a part of this application, in which:

Fig. l is a fragmental plan View showing one end of the blank from which my improved carton is formed;

Fig. 2 is a sectional isometric view looking in the direction of one corner of an erected carton;

Fig. 3 is an enlarged, fragmental sectional view taken along the line III--III of Fig. 2; and

Fig. 4 is a sectional view taken generally along the line IV-lV of Fig. 3.

Referring now to the drawing for a better understanding of my invention, my improved carton is formed from an integral blank 10 which is cut to the shape shown in Fig. 1 and is scored along parallel lines 11 inwardly of the sides thereof and along parallel lines 12 inwardly of the ends'thereof to define a main or bottom panel 13. The portion of the blank outwardly of the scored lines 11 define side walls 14 for the carton. The portion of the blank 10 outwardly of the scored lines 12 is scored along a line 16 to define with the scored lines 12 end walls 17 for the carton. The portion of the blank outwardly of the scored line 16 is adapted to fold inwardly against the end wall 1'? and is scored along a line 18 to define with the scored line 16 end fiaps 19 which are substantially equal in size to the end walls 17. The portion of the blank outwardly of the scored line 18 provides stiffening flaps 21 which overlie and engage the bottom panel 13, as shown in Fig. 2, when the carton is erected.

The blank 10 is scored along lines 22 at the sides of nited States Patent 2,788,168 Patented Apr. 9, 1957 ice the end walls 17, as shown in Fig. l, to provide substantially rectangular corner flaps 23, which serve as strengthening and reinforcing means for the corners of the carton. The corner flaps 23 are perforated or scored along lines 24 which extend diagonally across the flaps to provide inner and outer foldable, triangular sections 26 and 27, respectively. The inner foldable section 26 is folded inwardly, as shown in Figs. 2 and 3, against its outer section 27 so that it extends alongside the outer side of the adjacent side wall 14. When the blank is run through the cutting machine, glue is applied to the sides of the inner sections 26 which are to be positioned adjacent the side walls 14, and to the adjacent portions of the side walls whereby the inner sections 26 are secured rigidly to the side walls 14 when assembled.

The ends of the side walls 14 are cut-away as at 28 and the adjacent ends of the inner sections 26 of the corner flaps are cut away as at 29 to provide slots adjacent the end walls 17, when assembled, for receiving outwardly projecting locking tongues 31 formed integrally with the sides of the end flaps 19. The locking tongues 31 thus enter the slots at the ends of the side walls 14, as shown in Figs. 2 to 4 and thereby hold the carton in erected position.

From the foregoing description, the assembly of my improved carton will be readily understood. The blank 10 is cut and scored in the manner described above and the side walls 14 and end walls 17 are folded inwardly and upwardly to vertical position. The triangular sections 26 of the corner flaps 23 are then folded inwardly alongside the triangular sections 27 and the corner fiaps are folded inwardly alongside the outer side of the side walls 14. The triangular sections 26 are then secured to the side walls 14 by the glue applied therebetween in the manner described above.

With the corner flaps 23 secured to the side walls 14, the end flaps 19 are folded inwardly along the scored lines 16 whereby they lie alongside the inner surface of the end walls 17. As the end flaps are moved inwardly toward the end walls 17, the outwardly extending locking tongues 31 engage behind the slots 28 and 29 provided in the side walls 14 and corner flaps 23, respectively. The carton is thereby locked rigidly in erected position. With the carton thus assembled, the stiffening flaps 21 overlie and engage the adjacent ends of the bottom panel 13 thereby adding strength and rigidity to the carton.

When the carton is manufactured and is ready for shipment, the end flaps 19 are left in extended or unfolded position and the side walls 14 are moved inwardly onto the bottom panel 13. As the side walls move inwardly, the inner triangular sections 26 move therewith, thus causing the end wall 17 to be pulled inwardly. As the end walls 17 move inwardly, the outer triangular sections 27 unfold along the scored or perforated lines 24 whereby both triangular sections of the corner flaps 23 lie in a common plane between the side walls 14 and the end walls 17. With the carton thus collapsed, the end flaps 19 and the stiffening flaps 21 lie in common planes with the end walls 17 and overlie the side walls 14, whereby the collapsed carton takes up a minimum of shipping space.

To erect the carton for use, the side walls 14 and end walls 17 are raised, thus causing the triangular sections 26 and 27 to move into engagement with each other. With the side walls 14 and end walls 17 in vertical position, the end flaps 19 are folded inwardly, as already described, whereupon the locking tongues 31 engage behind the slots provided at the ends of the side walls 14 to lock the carton in erected position.

From the foregoing, it will be seen that I have devised an improved carton which may be readily moved from collapsed to erected position. By providing corner sections which permit both the side walls and end walls to be moved inwardly onto the bottom wall without creasing or bending the side and end walls, the carton is not weakened at the corners or sides adjacent the corners. By providing outwardly projecting locking; tongues on the end flaps which engage behind slots provided at the ends of the side walls, the carton is held rigidly in erected position and may be assembled by merely moving the end flaps inwardly against the end walls of the carton. Furthermore, the stiffening flaps formed at the free ends of the end flaps engage the upper surface of the bottom panel thereby adding further strength to the carton.

While I have described the main panel 13 as being a bottom panel, it will be apparent that where the carton is used as a top section of a'completed carton, the main panel 13 would then serve as atop panel.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore that only such limitations shall be placed thereupon as are specifically set forth in the appended claim.

What I claim is:

A collapsible carton formed of an integral blank and comprising a main panel hingedly connected to side and end walls, end flaps at the free ends of said end walls and adapted to fold inwardly thereof, inwardly foldable corner flaps at the sides of said end Walls and diagonally scored to provide inner and outer triangular foldable sections, each inner section being folded inwardly against its outer section and extending alongside the outer side of the adjacent side wall and secured thereto whereby the side walls overlie the mainpanel and the corner flaps overlie the ends of an adjacent side wall when the carton is collapsed, the ends of said side walls and the adjacent portions of said inner triangular sections being cut away to provide slots adjacent said end Walls, and outwardly extending locking tongues at the sides of said end flaps disposed to engage said slots when the carton is erected.

References Cited in the file of this patent UNITED STATES PATENTS 

